Saudi Arabia says it has deported more than 250,000 foreign migrant workers from the kingdom over the past three months.

The interior ministry said late on Tuesday that the foreigners had been residing in the country illegally and were in violation of labour laws. It did not elaborate.

The deportations began after 4 November with a nationwide campaign targeting many of the kingdom's 9 million migrant labourers after years of lax law enforcement.

Many of those deported were Ethiopians accused of crossing into Saudi Arabia illegally through its southern border with Yemen. Most foreign workers in the kingdom are from India, Pakistan, Bangladesh, Indonesia and the Philippines, as well as Egypt and Yemen.

Saudi authorities say deporting illegal foreign migrants will open more jobs for its own citizens.